I basically want to end the loading of a page if javascripting is disabled. Yes I pretty much want to show blank pages to users who have not detected JavaScripting.

I thought about including a php tag using exit; in a noscript tag

<noscript>
<?php 
echo 'This page REQUIRES JavaScripting to be enabled';
exit;?>
</noscript>

but wondered if this would affect users with JavaScripting enabled.

My question is will the server parse the php tag when it encounters it or will it only parse the php tag when the noscript tag is used when a visitor's JavaScripting is disabled?

PHP can't detect that. How about calling a PHP script with a .js command? That way if they don't have JS on, then the PHP script won't be called.

But really you should make it work without JS at all if you can, as a backup.

What you need to bear in mind is the order in which things are done on the web. The PHP Script is parsed by the server before the resulting HTML is even sent to the browser. Therefore, tags such as <noscript> have no effect at the time the PHP is being parsed. Think of any HTML outside the <? ?> tags as being echo'd by PHP, i.e.

<?php 
echo '<noscript>';
?>
<?php 
echo 'This page REQUIRES JavaScripting to be enabled';
exit;?>
<?php 
echo '</noscript>';
?>

That code will create an HTML document which will then be parsed by the browser. But since you have an exit statement in there, the </noscript> end tag will never be written out. All you will end up with is invalid html.

Wow the more I learn about JavaScript the more I would rather use PHP.

My problem

I wanted to use JS to read this XML data onto a webpage

<userlist>
 <member>
  <name>Bob Jones</name>
  <motto>Every day in every way I get better &amp; better!</motto>
  <id_number>1369420</id_number>
 </member>
</userlist>

So here's my well thought out solution. XML is a waste of time and largely unsupported so why bother? I'll just rename the XML file to members.TXT and replace the XML tags with (X)HTML tags and then use PHP includes to add the file to my page. I'm done, though I'm not proud, and I didn't have to use any JS or regex expressions.

JS is for manipulation of the page after it has been sent to the user. (client-side)
PHP is for manipulating of the page before it reaches the user. (server-side)

They really have 2 separate uses.

JS has support for XML. No use of regexs to parse an XML file:

var theXML = req.responseXML.getElementsByTagName("userlist");
var theMembers = theXML[0].getElementsByTagName("member");
var firstUsername = theMembers[i].getElementsByTagName("name")[0].firstChild.nodeValue;

That's what all the AJAX hubub is about. But unless you need to insert the name/motto/uid after the page has loaded, just make a DB and use PHP. Better security too.

I have some code which detects javascript with php.
It can be found at
http://snippets.bluejon.co.uk/
blujon

XML is a waste of time and largely unsupported so why bother?

As a programmer having several years of experience on this field, XML is far from being unsupported and a waste of time.

When you do things in your little corner, it might by overkill, but as soon as you need to exchange datas between differen systems (or applications) you don't manage, it's literraly a savior.

Probably you are throwing it because you were not using it in the right situation, or with the good approach, but trust me, it's VERY easy and fast to alter it to render nearly anything.

I develop every sites I do with XML and XSLT, and it does have reduced the templating and code handling time I spent on my pages.

And by the way, if you have heard about the DOM tree of your browser (you know, that thingy firefox include to let you inspect the source of a web page) ?
Well, it's pure XML. Javascript DOM functions are supported in every browser since IE 5.5 (he was the first) and since then almost every modern web browser can create a web page receiving XML and XSL.